Sheave drive assembly for flexible production tubing

Abstract

Flexible production tubing is wound about a reel for convenient transport to and from a well site. A submersible pump is attached to the end of the flexible tubing and is inserted through the well casing to a producing formation. The flexible production tubing includes a high strength injection core, a tubular production conduit, auxiliary hydraulic/pneumatic conduits, signal conductors, power conductors and a load bearing tension member. Insertion and withdrawal of the flexible tubing and pump are accomplished by a hydraulically powered drive assembly mounted above the well head. The production tubing is characterized by a generally pentagonal cross-section and is compressively engaged between a hydraulically powered drive sheave and a pneumatically biased idler sheave.

What is claimed is: 
     
       1. Apparatus for inserting and withdrawing flexible production tubing into and out of a well, said flexible production tubing having a first plurality of sidewall portions joined together and transitioning along one or more curved apex sidewall portions constituting a first frictional drive surface, and a second plurality of sidewall portions being joined by one or more curved apex sidewall portions constituting a second frictional drive surface; said apparatus comprising, in combination: a crown sheave mounted for rotation adjacent the well providing rotatable support for the flexible production tubing between the well and an external reel;   a drive sheave assembly disposed adjacent the well for inserting and retracting the flexible production tubing into and out of the well bore, said drive sheave assembly including a drive sheave having an annular groove formed by drive sheave sidewall portions which conform, in cross section, with the first frictional drive surface of the flexible production tubing and an idler mounted for pivotal movement into and out of engagement with the flexible production tubing, said idler sheave having an annular groove formed by idler sheave sidewall portions which conform, in cross section, with the second frictional drive surface of the flexible production tubing; and,   power means coupled to the idler sheave for driving the idler sheave into yieldable engagement with the second frictional drive surface of the flexible production tubing.   
     
     
       2. Apparatus for inserting and withdrawing flexible production tubing into and out of a well comprising, in combination: a crown sheave mounted for rotation adjacent the well providing rotatable support for the flexible production tubing between the well and a supply reel;   a drive sheave having an annular groove for engaging the flexible production tubing;   rotary power means coupled to said drive sheave for driving it in rotation;   an idler sheave mounted for pivotal movement into and out of engagement with the flexible production tubing, said idler sheave having an annular groove for receiving and engaging the flexible production tubing; and,   power means coupled to the idler sheave for driving the idler sheave into yieldable engagement with the flexible production tubing.